(function(document, window){
    var domEl = document.documentElement
    resizeEvent = 'orientationchange' in window? 'orientationchange': 'resize';
    recalc = function() {
    var clientWidth = domEl.clientWidth
    if (!clientWidth) return;
    domEl.style.fontSize = 100 * (clientWidth/375) +'px';
    }
    if (!document.addEventListener) return;
    window.addEventListener(resizeEvent, recalc, false)
    document.addEventListener('DOMContentLoaded', recalc, false)
}(document, window))